The timing steps of this circuit are indicated by a 7-segment display. The circuit was found in documentation from the 90s. The capacitor next to the 555 determines the timing steges.
In this circuit, the current capacity doubles, but is still of the order of microamps. The...
This circuit was obtained from an English magazine from 1977. The magazine no longer exists, but...
This well-known circuit triggers a relay when light striking the phototransistor is cut off. The...